Feeder devices



1970 J. A. NIELSEN 3,523,618

FEEDER DEVICES Filed Aug. 25, 1968 2 Sheets-Sheet l INVENTOR.

J0me Baez/:7 Mass ATTORNEYS ug- 1970 J. A. NIELSEN 3,523,618

I FEEDER DEVICES Filed Aug. 23; 1968 1 2 Sheets-Sheet2 mvmron.

Jmroe 17061187 N/HSM ATTORNEYS.

United States Patent ()1 ice US. Cl. 214-11 5 Claims ABSTRACT OF THEDISCLOSURE A feeding device for sequentially delivering single articlesto a conveyor, comprising at least two feeding stations each adapted tosequentially receive one article in a position in front of a releasestation in which releasable holding means are provided for preventingsaid articles from leaving the release station, actuation means operableto release said holding means, conveying means operable in response torelease of said holding means for moving said article away from saidrelease station towards the delivery end of said feeding stations butone as long as an article is passing the release station of this feedingstation in response to said holding means in this station being releasedso as to prevent overlapping of articles sequentially being releasedfrom different release stations, coding means located adjacent each ofsaid feeding stations and associated with code signal memoring means soas to be operable to set in said memory means a code signal for eacharticle to be delivered from the feeding stations, and code signaltransferring means operable to transfer said code signal from saidmemory means in any of said feeding stations to code signal receivingmeans in response to an article belonging to said code signal beingreleased from the feeding station.

The present invention relates to a feeding device for conveyor systemsand more particularly to a device for sequentially delivering singlearticles of goods to a conveyor from two or more feeding stations. Stillmore specifically though not exclusively the invention relates to afeeding device for automatic sorting apparatuses for post parcels andsimilar sorters.

During the last years different sorting equipments have been developedfor making the sorting of post parcels, flight luggage etc. more or lessautomatic. It is a common feature in these systems that the articles arefed one by one into the apparatus and a code for the destination of eacharticle is set by the operator as the article passes by a codingstation. Hereafter the article passes out on a conveyor line past anumber of discharging stations each corresponding to a certaindestination, and according to the code set by the operator theparticular article will be automatically diverted from the conveyor lineas it reaches the discharging station for the particular destination.Some of these sorters are able to work with a remarkable speed, butsince the actual speed of operation is limited by the manual codesetting procedure it will be apparent that the actual sorting capacitycannot be increased to the technical possible magnitude unless thecoding process can be accelerated. In some systems it will be possibleto prepare or provide the articles with detectable code means subject toautomatic reading or detection in a data reading destination selectorunit at the entrance to the sorting conveyor line or in each dischargingstation so as to actuate the means for diverting the article from theconveyor to a destination in direct response to local detection of thecode for this particular destination. In such cases it would be possibleto let two or more operators provide the articles with the correctPatented Aug. 11, 1970 means at the desired discharging station as thearticles pass by a coding station. Sorter systems have been developed inwhich according to this principle the articles pass an operator standingat a feeder station at the entrance to the conveyor line and setting acode at a key board according to the destination appearing in normalwriting on each article passing his position. The code set is recordedin a so-called driving register and when the driving velocity of thearticles on the conveyor line is known, it is possible to set the codeelectronically or otherwise follow the particular article until itreaches the discharge station corresponding to the code set. In thisstage the recorded code data will actuate the diverter means for thisparticular discharging station. 'It will be appreciated that in a systemof this nature where the coding of the articles is carried outsequentially as the articles enter the sorting machine, the sortingcapacity is effectively limited by the speed with which the operatorreads the destination on the single article and operates the key boardin accordance therewith, and practice has shown that this reading andcoding operation is in fact the bottle neck of the system. The articlesmay be delivered to the operator in a quick continuous flow and theautomatic sorting on or from the conveyor line may take place rapidly,but the reading and code setting by necessity takes some time.

It is the object of the invention to provide a feeding device for aconveyor or sorter line which is able to deliver articles one by one tothe conveyor line from at least two feeding stations in each of which anoperator may make articles ready for delivery to the conveyor and getthem delivered thereto without taking notice of to which times articlesare delivered from the other feeding station or stations.

Another object of the invention is to provide a feeding devicecomprising two or more feeding stations and provided with means ensuringthat the consecutive articles in the row of articles leaving the feedingdevice will show a suitable spacing from each other in order to enable awell defined and individual treatment of the articles in the conveyorline, such as removal or diversion from the conveyor.

Yet a further object of the invention is to provide a feeding devicecomprising at least two parallelly arranged feeding stations in each ofwhich an operator can read the data such as an address on the articlesand register the data for each article in a code setting register insuch a manner that the article may later, on the said conveyor orotherwise, be treated in accordance with the code set, irrespectively ofthe sequence in which articles are delivered from the plurality offeeding stations.

Conveyor systems are known in which articles from two lines are movedinto one row on a single line by means of a mechanical arrangementcomprising a retractable stop member at the delivery end of each of thetwo feeder lines, these stop members being mounted on a see-saw-likesupporting member ensuring that either one or the other stop member isin a protruding position in which it prevents article delivery from itsassociated feeder line while the other, respectively the first stopmember is in a retracted position allowing at least the first article inits associated feeder line to be delivered to the common line. Analternate delivery from the two feeder lines is obtainable by means ofan arrangement including in both feeder stations an arm which is presseddown by the article under delivery from the concerned feeder line, saidarm when pressed down causing the advancing means for the next articleon this line to stop and-when the article leaves the said arm-causingits associated stop member to move to its protruding stop position andthereby the other stop member to move to its released position, wherebyan article will be released from the other feeding line with its leadingedge in a certain distance from the rear edge of the article justdelivered from the first feeder line, viz a distance corresponding tothe distance between the stop member and the said arm. However, in theknown systems of this kind, there is no question of moving articles ontoa sorter line with individual code signals for the single articles beingregistered in each of the feeding stations and following the articles incorrect sequence as the articles are delivered to the common line.

According to one aspect of the invention, the feeding device comprisesat least two feeding stations each adapted to sequentially receive onearticle in a position in front of a release station in which releasableholding means are provided for preventing said articles from leaving therelease station, actuation means operable to release said holding means,conveying means operable in response to release of said holding meansfor moving said article away from said release station towards thedelivery end of said feeding device, means for blocking the holdingmeans of the release station in all feeding stations but one as long asan article is passing the release station of this feeding station inresponse to said holding means in this station being released so as toprevent overlapping of articles sequentially being released from thedifferent release stations, coding means located adjacent each of saidfeeding stations and associated with code signal memoring means so as tobe operable to set in said memory means a code signal for each articleto be delivered from the feeding stations, and means for transferringthe code signal for a given article to code signal receiving means inresponse to said article being released from the feeding station.

If the articles to be handled are all of the same length the blockingmeans in a second release station may be actuated by the release of theholding means in a first release station and deactivated by means of atiming device ensuring that the next article from the second stationdoes not leave the station until the article already delivered from thefirst station has moved so far towards the delivery end that there isspace behind it for the article from the second station. This kind ofautomatic non-overlapping control is usable where the articles are ofuniform length in each single of the feeding stations.

If the articles are of different lengths such as usual in case of postparcels, the deactuation of the blocking means may be controlled by afeeler operable to register the passage of the rear edge of an articleunder departure from a release station so as to ensure that the nextarticle from any release station cannot be released until the rear edgeof the first article has passed to a position in front of the leadingedge of the next article to be released. Such feeler means may beprovided as a photoelectric detecting device. When it is desired to workwith a certain spacing between consecutive articles for example inautomatic sorter systems, this is obtainable in a simple manner by theuse of a time delay means in the operative connection between the feelerand the blocking means or alternatively as known per se by locating thefeeler means in the desired distance in front of the release stations.

According to the invention the feeler means serving to actuate theblocking means may at the same time constitute means for detecting thelength of the article under delivery in order to later cause theactuation of an appropriate number of diverting members or otherhandling means in accordance with the length of the article, wherebyseparate length measuring means are avoided.

In the following the invention is described in more detail withreference to the accompanying drawing, in which FIG. 1 is a perspectiveview of one embodiment of a feeding device according to the invention,and

FIG. 2 is a block diagram of the control circuit thereof.

The feeder device shown in FIG. 1 comprises a feeding table 2 with twofeeding stations 4 and 6 separated by means of a longitudinal rib 8.These feeding stations are constituted by supporting rollers 10 mountedbetween the rib 8 and side frame portions 12 extending forwardly fromthe feeding table 2. The rollers 10 are rotated in anti-clockwisedirection by means of friction belts 14 connected to a motor not shown.The two feeding stations continue into a common conveyor section 16 offorwardly tapered configuration and consisting of a number of rollers 18rotated in anticlockwise direction by means of a friction belt 20corresponding to the belts 14. The conveyor section 16 continues in aconveyor line 22 constituting an automatic sorting, conveyor; thoughthis sorting conveyor does not in itself form part of the presentinvention, some of its functions will be described in more detail below.

Adjacent the front end of each of the feeding stations 4, 6 there isprovided a retractable stop plate 24 which in an upwardly projectingposition prevents parcels or other articles from being moved forwardlyfrom the feeding station. Each stop plate 24 is mounted on the free endof a lever 26 which at its rear end is pivotally secured to bracketmeans 28 so as to be swingable between a raised position shown in thestation 4 and a lowered position shown in the station 6. As a controlmeans for this movement there is provided a pneumatic cylinder 30underneath each of the levers 26.

Adjacent the front end of the rib 8 there is mounted a housing 32 for anelectric lamp sending a transverse light beam out to both sides of thehousing 32, and cooperating therewith there is provided a casing 34 fora photoelectric cell or photo resistor at each of the frame portions 12so as to be able to register the passage of any article leaving each ofthe feeding stations.

It will be readily understood that an article placed on the rollers 10will be moved into engagement with the stop plate 24 and moved furtheras soon as this stop plate is retracted to its lowered position. Aparcel 36 is shown in a position in which it has just left the feedingstation 4 and is now moving forwardly over the conveyor section 16. Itis desired to ensure that all articles will have the same travellingtime between the two ends of the conveyor section 16, but since some ofthe articles depending of their positions in the moment they arereleased from the stop plate 24 shall need a lateral displacement inorder to be guided into the narrower conveyor 22, this would cause adifference in travelling time between articles travelling close to thecenter line of the conveyor section 16 and articles travelling close tothe sides thereof in case these latter were guided inwardly by rigidside guiding rails; instead of such rigid guiding rails the conveyorsection 16 is provided with side guiding means in the shape of afriction belt 38 driven with a velocity having a forwardly directedcomponent equal to the advancing velocity of the articles on the rollers18. Hereby the articles will be moved with uniform longitudinal velocityon the conveyor section 16 irrespectively of their departure position inthe feeding stations.

Each feeding station is provided with a code setting box 40 having a keyboard 42 comprising a number of press buttons 44 enabling an operator toset a destination code for an article to be delivered from the feedingstation and a release button 46 for actuating the cylinder 30 in orderto release the article from the feeding station after the code has beenset. The system is particu larly adapted for use in connection withautomatic sorters for post parcels and the keys 44 are used to set adigital code corresponding to the address of the particular post parcel.The conveyor 22 constitutes the automative sorter line and along thisline there is located a number of receiving stations, means beingprovided at each of these stations for diverting to the particularstation all parcels travelling on the line 22 with this station asdestination. The operation of these diverting means is controlled by acontrol system adapted so as to actuate the particular diverting meanswith such a time delay after the code has been set and the article hasbeen released from the feeding station that the concerned article has inthe meantime travelled the distance exactly to this particular positionin which it will be engaged by said diverting means upon actuationthereof. Such systemshowever with one feeding station only-are generallyknown in the art and should therefore need no detailed description inthe pres ent connection.

The rollers 18 in the conveyor section 16 are driven with a velocitywhich is somewhat higher than that of the rollers in the feedingstations. The control system is so adaptedas also described inconnection with FIG. 2-that the stop plate 24 in each feeding stationupon retraction thereof is held in the retracted position until the rearedge of the article passes the photoelectric measuring equipment 32, 34,whereas the cylinder 30- is actuated to raise the stop plate to itsprojecting holding position as soon as the article is no longer breakingthe light beam on the photo cell 34. In order to ensure a correctoperation of the said diverting means it is important to provide asuitable spacing between consecutive parcels, and some spacing isnecessary already by the passage of the photoelectric means because itmust be ensured that the light beam is reestablished after the passageof each single parcel so as to enable the stop plate 24 to be operatedfor holding the next parcel back at least until the correct spacing fromthe foregoing parcel has been obtained. The driven rollers 10 act tomove all parcels in the feeding station forwardly so that when moreparcels are lined up therein there will usually be no spacing betweenthem. However, when the stop plate 24 is releasing the first parcel thiswill move out on the rollem 18 followed in the feeding station by theother parcels 1n the row, and since the rollers 18 will move the firstparcel away with increased speed a spacing to the next parcel willautomatically be obtained in this manner so that the photoelectric meanswill always register the passage of each single parcel.

In operation, the operator at each feeding station pushes a parcel outon the rollers 10, reads the address on the parcel, and operates thecode setting buttons 44 correspondingly. The parcel is moved by therollers 10 until it is stopped by the protruding stop plate 24. Theoperator, thereafter, presses the release button 46, and if no otherparcel is under release from the other feeding station the stop plate 24will hereby be moved to its retracted position to thereby release theparcel for further travelling; simultaneously, the code set on the box40 will be fed into an electronic register serving to actuate thediverting means adjacent the destination of the parcel on the line 22exactly when the parcel has reached this diverting station.

As soon as the rear edge of the parcel passes the light beam from thelamp 32 the photo cell 34 will cause the stop plate 24 to be raised intoitsstop position, and this is done almost instantaneously so that theleading edge of the next parcel, if any, will be stopped by the plate 24after the spacing provided for as described above. For ensuring a welldefined start of the parcel in response to the stop plate 24 beingretracted as well as a safe acceleration of the parcel on the firstrollers 18 in the conveyor section 16 there is provided a frictionallayer on the rollers in the neighbourhood of the stop plate 24 so thatthese rollers will get a good grip on the parcels, however withoutpreventing the roller 10 immediately before the plate 24 to rotate undera parcel held back by the plate 24.

The control means of each control box are connected to a common controlunit in which means are provided for ensuring that the stop plate 24 inone of the feeding stations cannot be released as long as the stop platein the other feeding station is released. When one stop plate 24 isreleased in response to the release button 46 being operated, this willautomatically cause the operative connection between the release button46 and the stop plate 24 in the other feeding station to be broken, andthe control unit is so adapted that this operative connection is notreestablished until the light beam to the photo cell 34 in the firststation has been reestablished upon passage of the rear edge of thearticle leaving this station, and in order to ensure the correct spacingthe said operative connection will first be reestablished with a certaintime delay after the light beam has been reestablished. The control unitmay be so adapted that both feeding stations are made parallellyoperable after the said tlme delay so that the next parcel will leavethat of the stations 1n WhlCll the release button 46 is first operated.Preferably, the control unit contains memory means for registering theoperation of the release button 46 in such a manner that the button maywell be operated whilst a parcel is leaving one of the stations, but therelease signal to the corresponding stop plate 24 will be given by thememory unit first when the condition for the release, i.e. a correctspacing from the foregoing parcel as determined by the photoelectricmeans in connection with the time delay unit has been reestablished.

In a preferred embodiment, the memory unit is designed so as to be ableto memorize two or four code settings and release signals from each ofthe control boxes 40. The parcels will then be delivered or released inthe same sequence in which the code settings from the two control boxeswere transferred to the memory unit by operation of the buttons 46. Thecontrol boxes 40 further have buttons for'cancelling of a code alreadyset, and for repeating a code already set.

It will be appreciated that the two operators may act entirelyindependent of each other and it will also be appreciated that thesystem described is in no way limited to the use of only two feedingstations.

The feeder device according to the invention may well be used inconnection with already existing sorter lines 22. Some of the knownsorters are provided with automatic spacing control means adjacent theinlet end of the conveyor line and a memory register for the codesettings fed to the sorter so as to provide for exact synchronisrnbetween parcel positions and the timed progress of the codings. Thismemory register may easily be fed from the said memory unit of thefeeding device, and it may even be practical to work with anintermediate memory register covering the passage of the parcels on theconveyor section 16. The memory unit that may be able to store forexample four code settings hereby transfers the code setting for anyparcel under departure from the feeding station to the said intermediatememory register which may contain for example five or six sequentialcode settings according to the maximal number of parcels being able totravel simultaneously on the conveyor section 16. As the parcelshereafter pass the automatic spacing control means on the sortingconveyor 22 the code settings are transferred further to the memoryregister on the sorter itself.

As mentioned, the coding and code transferring means belong to the knownart, and it is believed that the detailed construction of the circuitsin the said control unit of the feeding station should need no specialdescription since it will be no problem for persons skilled in the artto build up a unit showing the function-a1 characteristics describedabove.

In order to further exemplify the invention a block diagram of a controlcircuit for the feeder device is shown in FIG. 3. This control system isso adapted that one of the feeding stations takes precedence over theother station, i.e. parcels from the other station will not be releaseduntil a moment in which there is no parcel ready for delivery from thefirst station. Theoretically, this could mean that the operator at thesecond station should wait for a pause in the operation of the firststation, but in practice one operator will not be able to continuouslyfollow up the maximal delivery capacity of his feeding station so thatintervals will often occur in which parcels from the other station maybe released. For this reason the system will work almost as if the twostations had been controlled in parallel, without one taking precedenceover the other.

Generally, in the system shown, the digital code set in the control box42 is transferred to a driving register 50 as soon as a parcel isreleased from one of the feeding stations. According to known principlesthe binary destination code corresponding to the particular parcel isrepeatedly supplied to the driving register during the time in which theparcel is under passage of the photoelectric measuring equipment wherebythe length of the parcel is automatically detected. The code setting istransferred repeatedly by means of transferring pulses occurring at afrequency proportional to the advancing speed of the conveyor as forexample obtained by switch means actuated by constantly spaced actuatorsmounted in connection with the driving means for the conveyor. Inaccordance with the frequency of these pulses the code setting isthereafter advanced stepwise in the driving register 50 so as toelectronically follow the parcel in its movement along the conveyor.When the particular code setting or signal hereby reaches the drivingregister stage corresponding to the actual destination of the parcel thecode signal will here cause an actuation of suitable diverter means suchas a tilting mechanism for the supporting rollers of the conveyor or forcorresponding slats in a moved conveyor band to which the parcels aredelivered from the tapered conveyor section 16 of the feeder deviceshown in FIG. 1. Thus, when the parcel reaches its point of destination,as many rollers of slats as corresponding to the length of the parcelwill be tilted so as to let the parcel slide out into the receivingstation at this place without influencing the parcels immediatelypreceding and following the diverted parcel.

In FIG. 2 the diverter means are designated 52 and are shown located atdilferent points along the driving register proportional to the locationof the diverting stations along the conveyor. It will be appreciatedthat any suitable type of diverter mechanisms other than the saidtilting arrangement may also be used, for example socalled live arm ordead arm diverters.

When a destination code has been set in the control box 40 theparticular code is deposited in binary form in a memory unit 54. Whenthe release button 46 is thereafter operated the code signal istransferred to another memory unit 56 designated a queue register andcontaining four memory circuits arranged in series. The signals pass aselector 58 of the kind serving to transfer the signal to the firstmemory circuit in the queue register which is not already containing apreviously transferred code signal. The first code signal in the queueregister is adapted to be transmitted to the driving register 50 througha gate 60 in response to a trigger impulse being supplied through aconductor 62.

The control voltage for the system shown in applied through a wire 64which is connected to a switch 66 controlled by the stop member 24 whichin its raised position holds the switch in position I and in its loweredposition holds the switch in position II. When in position II the switch66 supplies control voltage to another switch 68 which in its tum iscontrolled by the photo cell 34 so as to assume position I when thephoto cell registers a light beam from the lamp 32 and in position IIwhen there is no beam hitting the photo cells. The voltage for thetrigger impulses from the said conductor 62 is supplied from the photocell switch 68 in the position II thereof, and it will be noted that nosuch voltage is applied as long as the stop member 24 assumes its raisedposition, i.e. the switch 66 is in position I, and furthermore as longas the photo cell registers a light beam from the lamp 32, the switch 68hereby being in position I. On the other hand, when the stop member 24moves down and releases a parcel, and when thereafter the parcel breaksthe light beam to the photo cell 34, the trigger wire 62 will beconnected to the voltage supply wire 64 through the switches 68 and 66and through a pulse switch 70 designated ADVANCING PULSES; this switchis operated intermittently with a frequency corresponding to theadvancing velocity of the parcels on the sorter conveyor so as to causea correctly timed delivery of code signals to the driving register 50.The gate 60 is connected to position I of the switch 68 so as to beclosed whenever the photo cell 34 registers a light beam from the lamp32; this arrangement serves to additionally ensure that no code signalsare transferred to the driving register as long as no parcel is passingthe photo cell, but the arrangement is not strictly necessary becausethe said trigger pulses may occur only when the switch 68 is in positionII, i.e. when the light beam is broken.

Through a wire 72 the queue register 56 is connected to a gate 74 in theconnection between position I of the switch 66 and a relay 76 foractivating the cylinder 30 to lower the stop plate 24. The wire 72transfer an opening signal to the gate 74 whenever there is a codesignal set in at least one of the memory circuits of the queue register56. Thus, the gate 74 is opened as soon as the release button 46 isoperated, whereafter the control voltage may proceed towards the relay76 in order to release the stop member 24. However, the gate 74 isconnected in series with another gate 78 connected to the control systemof the other feeding station so as to be closed whenever the stop member24 belonging to this feeding station is held in its lowered position,i.e. when a parcel is under departure from the second feeding station.Furthermore, in the control line to the relay 76 there is inserted adelay circuit 80 serving to prevent operation of the stop platereleasing means until a desired spacing from the foregoing parcel hasbeen obtained. When the release button 46 is operated and no parcel isunder departure from the second feeding station the control voltage fromthe line 64 will pass the switch 66, the gate 74, and the delay circuit80 to thereafter cause the relay 76 to retract the stop member 24 andthereby release the parcel, the destination code of which has been setin the first memory circuit of the queue register 56.

In the manner described above the parcel starts to travel out on theconveyor section 16, and a very short time after the release the frontedge of the parcel will break the light beam on the photo cell 34. Bythe lowering of the stop member 24 the switch 66 will be switched overto position II so as to pass the control voltage to the photo cellswitch 68. After the said very short time this switch will be shifted toits position II which causes the gate 60 to open and control voltage tobe supplied to the triggering system 70, 62. The trigger pulses willcause the first code signal in the queue register 56 to be repeatedlydelivered to the driving register 50 as long as the switch 68 is inposition II, i.e. as long as the parcel is actually passing the photocell 34. As soon as the light beam on the photo cell 34 is reestablishedupon passage of the rear edge of the parcel the switch 68 is shifted toposition I whereby the gate 60 closes and the trigger pulses arestopped. Through a wire 82 position I of the switch 68 is connected to arelay 84 for activating the cylinder 30 so as to raise the stop memberas soon as the light beam is reestablished in order to stop the nextparcel from directly following the parcel under departure. In the wire82 there is inserted a gate 86 having a connection 88 to position II ofthe switch 68 so as to be open when voltage is supplied to position II.In the connection 88 there is a holding circuit 90 including a capacityserving to hold the opening signal on the gate 86 a short time after thecontrol voltage has been removed from position II of the switch 68. Thegate 86, therefore, will be open in the moment the switch 68 shifts toposition I so as to enable a control signal to pass to the relay 84 toraise the stop member 24; simultaneously a control signal is applied toa shift unit 92 serving to cancel the code signal in the first memorycircuit of the queue register 56 and to deplace the following codesignals in the register one step towards the left so as to bring thenext code signal ready for delivery to the driving register 50 inresponse to further trigger pulses being applied through the wire 62 ata later moment.

When the relay 84 has been actuated to raise the stop plate 24 theswitch 66 will hereby be brought back to its position I, and if there isalready a new code signal present in the queue register 56 the gate 74will be open. If there is still no parcel under departure from thesecond feeding station also the gate 78 will be open, so that after acertain time as controlled by the delay circuit 80 the relay 76 willagain be actuated to cause retraction of the stop plate 24 whereafterthe described operation cycle is repeated and the next parcel releasedfrom the feeding station with prescribed spacing from the first parcel.It should be mentioned that when the switch 66 is brought into positionII in response to the stop plate 24 being lowered the control voltagewill pass to position I of the switch 68, i.e. in direction towards therelay 84 and the shift unit 92; however, since a short but neverthelessrelatively long time has gone since the control voltage was removed fromposition 11 of the switch 68 the voltage holding unit 90 has in themeantime caused the gate 86 to close so that the control voltage willnot reach the relay 84 or the shift unit 92 in response to the switch 66being brought to position II, and a short time thereafter the releasedparcel will break the light beam so as to cause the switch 68 to shiftto position II and thereby start the delivery of code signals to thedriving register 50.

With a few exceptions the control circuit for the other feeding station,shown in the lower half of FIG. 2, is built up in exactly the samemanner as the described control system of the first feeding station. Theswitch 66 registering the position of the stop plate 24 of the secondfeeding station has its position II connected to the gate 78 of thecontrol system described above so as to cause a closing of this gatewhenever the stop member 24 assumes its retracted position, i.e., when aparcel is under delivery from the second feeding station. As mentionedthis will prevent the release mechanism of the first feeding sta tion togo in operation until the stop member 24 is again brought to its raisedstop position. If the release button 46 of the first station has beenoperated during the delivery of a parcel from the second station thenext delivery from the first station will hereby automatically bedeferred until the stop member 24' is raised; since in this situationthe gate 74 is already opened the opening of the gate 78 in response tothe stop member 24' being raised will automatically cause the relay 76to be operated after the prescribed delay, so that also in this case aquick release though with correct spacing from the foregoing parcel willbe obtained independently of the manual activation of the system.

The gate 78 in the second feeder station is connected to the wire 72from the queue register 56 in the first station in such a manner thatthe gate 78' is closed whenever there is a signal on the wire 72, i.e.whenever there is one or more code signals remaining in the queueregister 56 of the first station. The operator of the second station maypreset the code of up to four parcels in the queue register 56', and thefirst of these code signals together with the corresponding first parcelin the second station will be transferred to the driving register 50,respectively the sorting conveyor as soon as there are no parcelswaiting or under departure in the first station. As mentioned this makesthe first station take precedence over the second station such as oftenfully usable in practice.

Obviously, the coupling of the two systems may be made otherwise, forexample with the use of a selector enabling the two stations to workalternately. A control system of this kind may in itself be made inseveral possible manners of which an example is indicated in FIG. 2 indotted lines. In this system the gate 78' is connected directly toposition II of the switch 66 as shown by the wire 100, and not to theconnection 72 between the queue register 56 and the gate 74, so that inthis case the two control systems are identical and also identicallyinterconnected, The gates 78 and 78' are through wires 102, respectively104 connected to opposite terminals of a selector 106 adapted to beswitched downwardly by activation of an operation member 108 andupwardly by activation of an operation member 110. These members 108,110 are operatively connected to the wires 82, respectively 82' so thatwhen a control signal is applied to the relay 84 the member 108 isactuated to switch the selector 106 down in order to connect the wire102 with the control voltage on the input line 112 of the selector 106.Hereby a closing voltage is applied to the gate 78 so that this gatecannot be opened until the selector 106 is switched back to its initialposition. This switching back is effected by the member 110 in responseto a control signal occuring in the wire 82', i.e. in response to thesecond feeding station having completed the delivery of one parceltherefrom. When the selector 106 is thereby switched back to theposition shown the gate 78 will be closed and the gate 78 openedwhereafter a parcel may be delivered from the first station. It will beappreciated that in this manner parcels will be alternately deliveredfrom the two feeding stations.

As indicated in FIG. 2 the driving register 50 has a first portion 51which is not connected to any diverter unit 52. This section 51geometrically corresponds to the tapering conveyor section 16 shown inFIG. 1. It is an important feature that the code signals from the queueregisters 56 and 56' are transferred directly to the driving registerbecause this involves that the photo cell 34, 34' are used both forcontrolling the correct spacing between consecutive parcels and fordetecting the length of each parcel leaving the feeding stations. Herebya high degree of simplicity is obtained in the device according to theinvention, since difierent functions are carried out by the same means.

Another aspect of the invention is the provision of the described meansfor providing a safe and well defined spacing between consecutivearticles leaving each of the feeding stations, and these means areperfectly usable in connection with sorters having one feeding stationonly.

FIG. 3 shows a simplified control system in which the two feedingstations are working in parallel using a single queue register beingadapted to receive code signals from both control boxes in the sequencein which the release buttons 46 and 46 are operated. The destinationcode signals from the box 40 include an additional identification signalspecific for this box, and the signals from the other box 46'correspondingly include another identification signal. The code signalto be transferred from the queue register to the driving register inconnection with the release of the parcel belonging to this signal,whether present in one or the other of said feeding stations, is firstpassed to a detector or selector unit reading the identification signaland causing the stop member 24 or 24' in the correct feeding station tobe retracted whereafter the parcel is delivered from the stationtogether with the destination code signal thereof.

In this embodiment there is used a single queue register designated 120.As in FIG. 2 the control boxes 40 and 40' are provided with memory units54 in which the code set by means of the keys 42 is temporarily storedin binary form until it is transferred to the queue register by means ofthe release button 46. The selector 58 shown in FIG. 2 is here includedin the queue register and connected in parallel to the two memory units54 and 54' in such a manner that any code signal delivered from any ofthese control boxes will be set in the first memory unit of the queueregister which is not already containing a previously transferred codesignal. The memory units 54 and 54' are so adapted that a code signalreleased therefrom will automatically be completed with anidentification code signal referring to either the unit 54 or the unit54' as the case may be, and the memory units in the queue register areadapted to also memorize this identification signal. An interconnection122 is established between the two boxes 40 and 40 so as to block therelease button of one box during the actuation of the release button ofthe other box whereby it is prevented that signals from the two boxesmay be simultaneously applied to the same memory unit in the queueregister 120. Provisions are also made, in a manner not indicated, toblock the release buttons of both boxes when code signals have been setin all the memory units of the queue register.

As soon as the first code signal is transferred to the first memory unit124 in the queue register this signal is transmitted to a selector 126passing the destination code signal further towards the driving register50 and besides capable of reading the identification signal mentionedabove; an indentification signal from the unit 40, 54, i.e. box I, willcause the selector to actuate a relay 76 serving in its turn to actuatethe cylinder 30 to retract the stop member 24 in that of the feedingstations which belong to the said box I. On the other hand, if thesignal from the first unit 124 in the queue register originates from theother box unit 40, 54' (box II) the selector 126 will read thecorresponding identification signal and cause a relay 76' to retract thestop member 24' in the other feeding station. A gate 128 is arranged inthe connection between the selector 126 and the driving register 50, andthis gate is adapted to be closed as long as both of the photo cells 34,34' registers the light beam from the lamp 32, i.e. as long as no parcelis under delivery from any of the feeding station; it will beappreciated that under these circumstances no code signals aretransferred to the driving register.

As soon as one of the stop members have been re tracted in response tothe selector 126 reading the identification signal contained in the codesignal to be delivered together with the parcel under delivery, thisparcel will start moving out onto the conveyor section 16 and therebybreak the light beam to the photo cell in its feeding station. The photocell controls a switch 130 applying control voltage on an output line132 as long as the photo cell does not receive light from the lamp 32.This voltage is through a wire 134 applied to the unit 70 which asdescribed in connection with FIG. 2 serves to generate output pulsescorresponding to the velocity of the conveyor means in the conveyorsection 16 as well as the sorter line 22. These pulses are through wire62 applied to the gate 128 so as to repeatedly open and close this gateas long as the released parcel is under passage of the photo cell. Bythis operation of the gate 128 the code set in the first memory unit 124of the queue register 120 will intermittently pass to the drivingregister 50 so as to fill up as many units therein as corresponding tothe length of the parcel being released. When the rear edge of theparcel has passed the photo cell the light beam will be reestablished soas to cause the switch 130, respectively the switch 130 to shift toposition light after dark and thereby remove the control voltage fromthe wire 132 so as to close the gate 128. Through a wire 136 the pulsegenerating unit 70 still transfers advancing pulses to the drivingregister '50 in order to provide trigger impulses thereto so as to causethe code settings therein to move forwardly through the register in astepwise movement proportional to the advancing velocity of the parcels.

As soon as the switch 130 respectively 130 is shifted to the positionlight after dark a relay 84, respectively 84 will be actuated and causethe retracted stop plate 24 or 24 to be raised to its stop position;this takes place almost immediately after the released parcel has passedthe photo cell so that the next parcel in the row in the concernedfeeding station will hit the stop plate and be held back thereby. Inthis position of the switch 130 respectively 130' control voltage willalso be applied to an output wire 138 which is connected to the selector126 through a unit 140 which serves to send a cancelling impulse to theselector 126 so as to cancel the reading of the identification codesignal and to prepare the selector to react on the occurrence of a newidentification code signal. Simultaneously, from the wire 138, controlvoltage is applied to a shift unit 142 through a delay circuit 80, andthe shift unit 142 is connected to the queue register so as to cause thecode setting in the first memory unit 124 to be cancelled and thefollowing queue of code sigals to be advanced one step towards the leftso as to bring a new code signal into the memory unit 124. At this timethe switch 130, respectively has shifted to position steady light sothat the signal on the selector 126 from the cancelling unit has ceased.Therefore, the selector 126 now reads the identification code signal ofthe new code signal in the unit 124, whereafter the described operationcycle is repeated. The delay unit 80, as in the embodiment previouslydescribed, serves to delay, the shift in the queue register until thepreviously released parcel has moved sutficiently to ensure the desiredspacing from the next coming parcel.

Due to the identification code signals used the device will workcorrectly independent of in which sequence the release buttons in thetwo control boxes are actuated, and of course the queue register maycontain as many memory units as desired, for example corresponding tothe maximal number of parcels which can be lined up in the two feedingstations.

It will be appreciated that the system involves no limitation as to thenumber of different feeding stations, since the device will work in themanner described when the code signals from each of the feeding stationsare completed with a specific identification code signal for theparticular feeding station, since the selector 126 will then cause thestop member in the correct feeding station to be retracted in connectionwith the destination code signal for the parcel to be released beingtransferred to the driving register 50.

It is not even necessary that each of the stations are provided withseparate photo cells; thus, in FIG. 1 the lamp 32 may be removed andmounted instead of the photo cell 34' so that the photo cell 34 willregister the parcel delivery from both of the stations shown. The photocell switches 130 and 130' are connected in parallel and might thereforebe substituted by one switch only. The relays 84 and 84 would in thiscase be substituted by one relay connected further in the circuits insuch a manner that upon actuation it would cause a stop member loweredin any of the feeding stations to be raised. Since there can only be onestop member lowered at a time there are no difiiculties in providing asystem in which the lowering of the stop members are selectivelycontrolled by the selector 1 26 whilst the returning of the stop membersto the holding position is controlled by a unit common to all stopmembers, for example with the use of a purely mechanical resettingsystem including a raisable cross beam extending crosswise underneathall the carrier arms 26 of the stop members 24 so as to raise anylowered stop member when it is raised itself in response to the relay 84being actuated. Alternatively the relay '84 may send an actuation signalto separate raising relays in all feeding stations at one time wherebyan actual raising of the stop members will only take place in thestation in which the stop member has been lowered.

What is claimed is:

1. A feeding device for sequentially delivering single articles to aconveyor, comprising at least two feeding stations each adapted tosequentially receive one article in a position in front of a releasestation in which releasable holding means are provided for preventingsaid articles from leaving the release station, actuation means operableto release said holding means, conveying means operable in response torelease of said holding means for moving said article away from saidrelease station towards the delivery end of said feeding device, meansfor blocking the holding means of the release station in all feedingstations but one as long as an article is passing the release station ofthis feeding station in response to said holding means in this stationbeing released so as to prevent overlapping of articles sequentiallybeing released from different release stations, coding means locatedadjacent each of said feeding stations and associated with code signalmemoring means so as to be operable to set in said memory means a codesignal for each article to be delivered from the feeding stations, andcode signal transferring means operable to transfer said code signalfrom said memory means in any of said feeding stations to code signalreceiving means in response to an article belonging to said code signalbeing released from the feeding station.

2. A feeding device as claimed in claim 1, in which each of said feedingstations is operable to receive at least two aligned articles, saidconveying means comprising at first continually and endlessly movingsupporting surface located in each feeding station and being operable tofrictionally engage the articles resting thereon so as to tend to movethe articles forwardly and against said holding means and a secondcontinually and endlessly moving supporting surface located in a commonconveyor section in front of the holding means of all feeding stationsand also operable to frictionally engage an article released from any ofsaid feeding stations in order to move the released article towards thedelivery end of said feeding device, said second conveying means beingdriven at a speed higher than that of said first conveying means, feelermeans operable to register the passage of the rear edge of a releasedarticle being located adjacent said releasable holding means and beingoperatively connected with means for actuating said holding means so asto bring said holding means to their stop position in response to therear edge of the released article passing said feeler means.

3. A feeding device as claimed in claim 1, in which articles from allfeeding stations are delivered to a common conveying section the sidewalls of which are tapering towards a delivery end therefor, saidtapering sides being defined by continually and towards said deliveryend endlessly moving wall portions capable of frictionally engaging aside portion of an article being moved thereagainst, whereas said movingwall portions are driven at a speed having a velocity component in themoving direction of the conveying means in said common which issubstantially equal to the speed of said conveying means.

4. A feeding device as claimed in claim 1, in which feeler means fordetecting the passage of the rear edge of a delivered article past saidholding means of any feeder station are provided so as to causeactuation of returning means for bringing the holding means to theirstop position in response to said passage, said feeler means alsoserving to register the passage of the front end of the releasedarticle, and in which means are provided for detecting the length ofsaid article, said length detecting means being actuated by said feelermeans in response to passage of the front end of the article anddisactuated by said feeler means in response to passage of the rear edgeof the article.

5. A feeding device as claimed in claim 1 in which said coding means areadapted to provide each code signal transferred to said memory meanswith an identification code signal specific for each of the differentfeeding stations, whereas selector means are provided for reading theidentification code signal of any article under release from the feedingdevice so as to cause retraction of the holding means in the feedingstation from which the identification signal originates.

References Cited UNITED STATES PATENTS 3,327,836 6/1967 Burt 214-11 XRGERALD M. FORLENZA, Primary Examiner R. B. JOHNSON, Assistant ExaminerUS. Cl. X.R. 198-32

